I need to make some repairs to the transmission tunnel on the Sabre Six, it lifts out in two pieces so is now indoors and easy to get to.
I'm not worried about the cosmetic finish, as there's carpet stuck (well, unstuck actually) on the surface.
What's the best way to clean the existing surface so that new glass will stick? I'm planning to reinforce both the underside and the outer surface.
All suggestions and contributions gratefully received, with thanks in advance.
Philip

A wire wheel followed by thinners or acetone to remove the adhesive, then feather the edges with a stone wheel in an angry grinder. Lay up as required. No need to do both sides as the feathering should go down to the backside.

One trick that I used for many years in mending fibreglass fairings on my race bikes was to drill a few holes around the keyed area, stick tape on the backside and when the resin is laid down they act as sockets for the resin plugs. It helped making sure that vibration never played a part in separating the join, or so it seemed.

I'm using clear plastic sheet from the front of a gift box thingy; once the resin is set I'm finding it peels away easily and leaves a super-gloss finish - far too "Cheshire" for my transmission tunnel, but it'll be hidden under the carpet anyway.
TrevorG - thanks for the "holes" tip - a good idea methinks.
Just waiting for some bits from Spalding Fasteners to fix everything in place, which raises the question - it looks like originally the tunnel uses self-tappers to screw directly into the floor (which looks to be about 3/4" thick fibreglass). Is this the standard fixing method?

- it looks like originally the tunnel uses self-tappers to screw directly into the floor (which looks to be about 3/4" thick fibreglass). Is this the standard fixing method?

If you have the original floor, it will be plywood covered in a layer of fibreglass as all Sabre Sixes, Sabre fours just had plain plywood floors. Fixing with self tappers was the original way of fixing the tunnel to the floor.